1. Field of Invention
This invention relates generally to a light box assembly in which a light bulb within the box serves to illuminate a film transparency placed behind a semi-reflective mirror mounted on the face of the box whereby the transparency image is visible only when the bulb is energized, and more particularly to an assembly of this type which is installable in a crib occupied by an infant and is interactive with the infant, the assembly having incorporated therein an electronic monitor which radio-transmits the sounds of the infant to a receiver in the hearing range of the infant's caregiver.
2. Status of Prior Art
It is known in the toy field to provide a "Magic Mirror" in which placed behind a semi-reflective mirror is a light box covered by a film transparency. When an electric light bulb within the box is turned on to illuminate the transparency, a child looking at the mirror then does not see his own reflection, but the illuminated image, for the mirror is then effectively transparent.
Also included in a Magic Mirror toy is a sound unit which when the bulb on the light box is turned on, then reproduces recorded sounds appropriate to the image being presented. Thus if the image is that of a dog, the reproduced sounds would be that of a dog barking.
Essential to a Magic Mirror and to an assembly in accordance with the invention is a mirror which in one mode of operation is effectively transparent and in another is effectively reflective. For this purpose the mirror must be a semi-reflective mirror.
A conventional plane mirror is fabricated by evaporating a metallic film on the rear surface of a transparent plate made of glass or acrylic plastic material. In most mirrors, the reflecting film is aluminum which is deposited on a substrate by evaporation in vacuum. The advantage of aluminum is that it has a broad spectral band of high reflectivity. Almost all aluminum-coated mirrors are "overcoated" with a thin protective layer, such as a layer of magnesium fluoride.
While a conventional aluminum-coated mirror has an average reflectivity of close to 90 percent, mirrors are known whose coating imparts semi-reflective characteristics thereto. Thus a beam impinging on a semi-reflective mirror is split into two parts, one being transmitted through the mirror, the other being reflected thereby.
If therefore the face of a light box is covered by a semi-reflective mirror behind which is a film transparency, then when the box is dark, an observer looking into the mirror sees his own reflection. But if the box interior is illuminated, the observer then sees the image of the transparency, for the mirror is then operating in a light transmitting mode.
The concern of the present invention is with a light box and mirror assembly that is installable in a crib or other enclosure occupied by an infant, the assembly being interactive with the infant in a manner to be later explained.
The most difficult aspect of infancy from a mother's standpoint lies in the sleep habits of her infant. Whether an infant lying in a crib or other enclosure is able to sleep soundly depends on two factors, one being physical and the other psychological. The physical factor turns mainly on whether the infant is hungry or in pain, for in either case the infant will be unable to sleep and will cry out to attract its mother's attention. But many infants who are not disturbed physically, are unable to sleep soundly because they are in a state of anxiety.
An infant's existence centers on its mother, and a sense of security in regard to its mother is therefore essential to the infant's proper psychological equilibrium. All infant's, however well cared for, remain anxious as to their mother's whereabouts. This insecurity does not vanish in later years, for many pre-school children carry security blankets to reduce anxiety.
The crib in which an infant lies is usually placed in the mother's bedroom or in a nursery adjacent this bedroom so that should the infant cry out, the mother will be aroused from sleep and attend to her baby. But whether in the course of a night the mother is awakened by her infant because the infant is physically uncomfortable or in a state of anxiety, in either event, the mother's sleep is interrupted. A mother's loss of sleep is perhaps the most exhausting aspect of raising an infant.
Of prior art interest is the patent to Zisholtz 4,640,034 which discloses a playback device activate by the sound of a crying child to play a recording of the mother's voice. It is also known to provide an electronic monitor to radio-transmit the sounds made by an infant in a crib to a receiver in the necessity of the infant's mother or caregiver.
The drawback of a conventional electronic monitor is that it does not discriminate between gurgling or playful sounds emanating from an infant and loud crying sounds. Hence the mother at the receiving end of the monitor is continuously alerted to whatever sounds her infant makes rather than only to those sounds that reflect a disturbed state and therefore requires her attention.